This is a multicenter, open-label, two arms, randomized, phase I/II study evaluating the safety and tolerability as well as some activity parameters of TG4050 in patients with squamous cell carcinoma of the head and neck (SCCHN).

Inclusion Criteria:

1. Signed written informed consent
2. Newly diagnosed stage III or IV, amenable to surgery (AJCC 8th edition) squamous-cell carcinoma of the oral cavity, oropharynx, hypopharynx or larynx
3. Female or male patients, aged at least 18 years
4. Patients in Complete Response after treatment of their primary tumor.
5. Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1.
6. Adequate hematological, hepatic and renal functions

Exclusion Criteria:

1. Patients with carcinoma of the nasopharynx, squamous cell-carcinoma of unknown primary, squamous cell carcinoma that originates from the skin and salivary gland or paranasal sinus, non-squamous histologies.
2. Prior exposure to anti-cancer vaccines and any antibody targeting T-cell co-regulatory proteins such as anti-PD1, anti-PDL1 or anti-CTLA4 antibodies.
3. Other active malignancy requiring concurrent systemic intervention.
4. Patients with previous malignancies other than the target malignancy to be investigated in this trial
5. Known history of positive testing for Human Immunodeficiency Virus (HIV) or known Acquired Immune Deficiency Syndrome (AIDS)
6. Clinical or laboratory history or evidence of Hepatitis C Virus (HCV) or Hepatitis B Virus (HBV) indicating acute or chronic infection
7. Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive hCG laboratory test (> 10 mIU/mL)
8. Treatment with another investigational agent since the beginning of the screening period
9. Uncontrolled intercurrent illness